1. Field of the Invention
The present invention is directed to a method and a device for controlling an actuator in a motor vehicle.
2. Description of Related Art
A digital regulation in an engine controller is frequently used to regulate electrically controlled actuators in a motor vehicle, e.g., a throttle valve, a charge motion valve, an exhaust gas recirculation valve, a bypass valve for a compressor, etc. In order to avoid damage to the respective actuator, it must be prevented that a mechanical stop of the respective actuator is approached too quickly. In order to ensure this, an offset to the stop is established so that the actuator may be moved quickly up to this offset. However, an increased leakage mass flow is a condition of this offset. An alternative approach uses a setpoint value change limitation using a filter, for example. A change in the setpoint value for the position of the actuator is limited to a predefined setpoint value according to the setpoint value change limitation. The setpoint value change is limited to such a low value that it is able to be ensured that the actuator does not approach the stop too quickly. If this setpoint value change limitation is active across the entire range of predefinable setpoint values for the position of the actuator, it results in the regulation of the position of the actuator to the corresponding predefined setpoint value being needlessly slow. A better approach is to activate this slow setpoint value change limitation only when the predefined setpoint value is between the stop and a predefined threshold value assigned to the stop.